School Infection Control Handbook - 2010

Chapter 4: Selection of Products, Dispensing Equipment, and Application Systems

Dwell time – Dwell time is product specific. All disinfectants are tested and labeled for the specific amount of time they must remain in contact with the surface to kill the microbes. The times listed are approximate only. EPA toxicity categories require the following warnings –

Signal Word

Category

On the Basis of

DANGER, POISON (skull and crossbones)

I Highly toxic II Moderately toxic

Oral, dermal, or inhalation toxicity Skin or eye irritation or dermal sensitization

WARNING

CAUTION

III Slightly toxic The results of all required acute toxicity studies

IV Relatively

The results of all required acute toxicity studies

CAUTION

nontoxic

Information – Sources of information include the MSDS; Scorecard (http://www.scorecard.org/chemical-profiles); the Pesticide Action Network’s Pesticide Database (http://www.pesticideinfo.org); and product information sheets. pH – pH is a measure of how acidic or basic a product is. Look for products with a neutral pH of 7 or as close to this number as possible. PPE – PPE may be required for the concentrated form of some products but not for the ready-to-use or prediluted form. Check the label and the MSDS. Precleaning – Except for disinfectant cleaners that are tested to disinfect in the presence of 5% organic matter, all other disinfectants require precleaning. Best practices recommend cleaning first and then disinfecting for optimal efficiency.

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